Chairs and seatback hinges are generally known. Typically, a chair comprises a seat and a seatback interconnected by some structure. The structure connecting the seat and the seatback can be rigid, such as a metal elbow and flange, or it can provide some flexibility, like a spring.
Chair users tend to enjoy the ability to recline, as it provides enhanced comfort. However, chair users also enjoy having support for sitting in an upright fashion. Traditionally, providing both advantages; stiffness and flexibility, required the use of one or more metal springs, such as coil springs.
Using metal components in chairs, such as for a spring connecting a seat to a seatback, poses substantial cost and complexity to the production and sale of a chair. A user may be required to assemble the chair and properly install the spring. If the spring is not properly installed, then the chair will not provide the desired flexibility and stiffness. Additionally, metal springs rust and can make noise while in operation.
In contrast, using plastic components in chairs has the advantage of reduced cost. However, plastics are often not suitable for structural members, because plastics tend to deflect and deform when placed under stress, and traditionally have poor rebound characteristics. Flexible plastic chairs are often irreparably bent, which fails to deliver the desired support. Also by the same token, stiff plastic chairs are often so hard that a great deal of force is required to induce any deflection, with is uncomfortable and unpleasant for the user.
Accordingly, a need exists for a plastic chair flexor that provides both the flexibility and stiffness desired by a user.